Warehousing has long been a global industry; warehouses are integrally linked to commerce and transportation of goods—by rail, sea, air and road. Warehouses may be classified by the type of products stored: food products stored in dry, chilled or frozen sections; clothing or textiles; construction equipment or materials; machinery or machine parts. In the United States in 1995, for exemple, 1,877,000 workers were employed in trucking and warehousing (BLS 1996); this statistic cannot presently be disaggregated into workers by warehouse type or category. Warehouses might sell directly to external (retail) or internal (wholesale) customers, and the quantities retrieved for customers may be either full-pallet or less-than-full-pallet (one or more cases selected from a single pallet). Mechanical means (fork-lifts, conveyors or automatic storage and retrieval systems (AS/RS)) may be used to transport full-pallet or less-than-full-pallet loads; or workers, working without pallet movers and conveyors, may manually handle stored materials. Regardless of the nature of the business, the products stored or the mode of transportation servicing the warehouse, the basic layout is quite uniform, although the operational scale, terminology and technology will likely differ. (For additional information on AS/RS in warehousing, see Martin 1987.)

Products are delivered by shippers or suppliers to a receiving dock, where they are then entered into either a manual or computerized inventory system, assigned a storage rack or “slot” location (an address) and then transported to that location, usually by mechanical means (conveyors, AS/RS, fork-lift trucks or tractors). Once a customer order is received, the desired containers or cases must be retrieved from their slot location. Where full pallets are retrieved, mechanical means (a fork-lift or tractor operator) are used (see figure 1). When less than a full pallet load (one or more cases from a rack or slot) is to be retrieved, manual material handling is required, using a worker called a selector, who will choose the desired number of cases and place them either onto a mechanical pallet mover, a push cart or a conveyor. The individual customer order is assembled onto a pallet or similar container for shipment to the customer; a label, tag or other mark containing invoice/billing and/or routing instructions is then applied. This task may be performed by the order selector or fork-lift operator, or, where conveyors are used to deliver single cases for final assembly, by an assembler. When the order is ready for shipment, it is loaded by mechanical means onto the truck, trailer, railroad car or ship. (See figure 2).

Figure 1. A fork-lift truck in a warehouse in the United Kingdom being loaded with apples.

Figure 2. A dockworker in the United Kingdom using lifting machines to move quarters of beef.

Approximately 60% of the work activity in the warehouse is directly related to travel; the remainder relates to manual material handling. Aside from the important work of clerks, dispatchers, cleaners, supervisors and managers, the main work of the warehouse relating to the transporting and handling of goods is performed primarily by two classes of workers: fork-lift operators and selectors.

Intense worldwide competition and the rapid entrance of new firms have created the drive for increased labour and space efficiency, spawning a new discipline called warehouse management systems (WMSs) (Register 1994). These systems are becoming increasingly less expensive and more powerful; they rely on computer networks, bar coding, computer software and radio-frequency communications systems to vastly increase management and control of warehouse inventory and operations, allowing warehouses to improve customer order response times and responsiveness while dramatically increasing inventory accuracy and reducing costs (Firth 1995).

WMSs essentially computerize inventory and order dispatch systems. When incoming product from a supplier or shipper arrives at the receiving dock, bar code scanners record the product code and name, instantly updating the inventory database while assigning the incoming product an address in the warehouse. A fork-lift operator is then alerted to pick up and deliver the stock via a radio-frequency communications system mounted on the vehicle.

Orders from customers are received by another computer program which looks up the product address and availability of each item ordered in the inventory database and then sorts the customer order by the most efficient travel path to minimize travel. Labels with the product name, code and location are printed out for use by the order selectors who must then fill this order. While these features clearly help improve customer service and improve efficiency, they are important preconditions for engineered work standards (EWSs), which may pose additional health and safety hazards for both fork-lift operators and order selectors.

Information about each order—the number of cases, travel distances and so on—which is generated by the order dispatch programme can be further combined with standard or allowed times for each activity to calculate an overall standard time for selecting a particular customer order; it would be extremely time-consuming and difficult to retrieve this information without the use of the computer hardware and databases. Computer monitoring can then be used to record the elapsed time on each order, compare the actual with the allowed time and then compute an efficiency index, which any supervisor or manager can look up by pressing a few computer keys.

Warehouse EWSs have spread from the United States to Australia, Canada, the United Kingdom, Germany, Austria, Finland, Sweden, Italy, South Africa, the Netherlands and Belgium. While WMS systems themselves do not necessarily add safety and health hazards, there is considerable evidence to suggest that the resulting increased workload, lack of control over work pace and the impact of increased frequency of lifting contribute significantly to increased injury risk. In addition, the time pressure imposed by work standards may force workers to take risky short cuts and not utilize proper safe work methods. These risks and hazards are described below.

Hazards

In the most basic warehouse, regardless of the level of technology and computerization, there are a myriad of basic health and safety hazards; modern WMSs can be linked with a different order of health and safety hazards.

Basic health hazards begin with potentially toxic materials which may be stored in warehouses; examples include petroleum products, solvents and dyestuffs. These require proper labelling, employee education and training and an effective hazard communication programme (including MSDSs) for all affected workers, who often know little about the health effects of what they are handling, much less proper handling, spill and clean-up procedures. (See, for example, the ILO Chemicals Convention, 1990 (No. 170), and Recommendation, 1990 (No. 177).) Noise may be present from gasoline or LP-powered fork-lifts, conveyors, ventilation systems and pneumatically-actuated equipment. Additionally, workers who operate such equipment may be subject to whole-body vibration. (See, for example, the ILO Working Environment (Air Pollution, Noise and Vibration) Convention, 1977 (No. 148), and Recommendation, 1977 (No. 156).)

Both fork-lift operators and selectors may be exposed to diesel and gasoline exhaust from trucks at the loading and receiving docks, as well as from fork-lifts. Lighting may not be adequate for fork-lift and other vehicle traffic or for ensuring proper identification of products desired by customers. Workers assigned to work in cold and frozen storage areas may experience cold stress from exposure to cold temperatures and air recirculation systems; temperatures in many freezer storage areas can approach –20ºC, even without wind chill factors being considered. Moreover, since few warehouses are air conditioned during warm months, warehouse workers, particularly those performing manual material handling, may be exposed to heat stress problems.

Safety hazards and risks are also many and varied. Besides the more obvious hazards evident when pedestrians and any motor-driven vehicle are put into the same work area, many of the injuries occurring among warehouse workers include slips, trips and falls from floors not kept free of ice, water or spilled product or that are poorly maintained; a number of injuries involve fork-lift operators who slip or fall while mounting or dismounting their fork-lift trucks.

Workers are often exposed to falling product from overhead racks. Workers may be caught in or between fork-lift masts, forks and cargo, resulting in serious physical injury. Wooden pallets handled by workers often result in exposure to slivers and related puncture wounds. Using knives to cut apart boxes and cases often results in cuts and lacerations. Workers who move boxes or containers on or off conveyors may be exposed to in-running nip points. Selectors, assemblers and other workers engaged in manual material handling are exposed to varying degrees of risk of developing low-back pain and other related injuries. Weight-lifting regulations and recommended methods for materials handling are discussed elsewhere in the Encyclopaedia.

Recordable injuries and lost workday cases in the US warehouse industry, for example, are considerably higher than those for all industry.

Data regarding injuries (and particular back injuries) among grocery order selectors, the group at greatest risk from lifting-related injuries, are not available on a national or international scale. The US NIOSH, however, has studied lifting and other related injuries at two grocery warehouses in the United States (see US NIOSH) and found that “all order selectors have an elevated risk for musculoskeletal disorders, including low-back pain, because of the combination of adverse job factors, all contributing to fatigue, a high metabolic load and the workers’ inability to regulate their work rate because of the work requirements” (NIOSH 1995).

A comprehensive application of ergonomics to the warehouse should not be confined to lifting and to order selectors. A wide focus is required, involving detailed job analysis, careful measurement and assessment (part of the job analysis begins with the job safety analyses below). A more comprehensive look at the design of racks and shelves is required, as is establishment of a closer working relationship with suppliers to design or retrofit fork-lift controls to reduce ergonomic risk factors (extensive reaches, foot flexion and extension, winging, awkward neck and body positions) and to design containers that are less heavy and bulky, with handles or grips to reduce lifting risk.

Corrective Actions

Basic health hazards

Employers, workers and trade unions should cooperate to develop and implement an effective hazard communication programme which emphasizes the three following fundamentals:

1. adequate labelling of all toxic substances
2. availability of detailed MSDSs that provide more detailed information about health effects, fire, reactivity, PPE, first aid, spill clean-up and other emergency procedures
3. regular and relevant worker training in proper handling of these substances.

Lack of an effective hazard communication programme is one of the most frequent standards violations cited in this industry by the US Occupational Safety and Health Administration (OSHA).

Noise and vibration from mechanical equipment, conveyors and other sources require frequent noise and vibration testing and worker training, as well as engineering controls where needed. These controls are most effective when applied at the source of the noise in the form of noise insulation, mufflers and other controls (since most fork-lift operators are seated on top of the engine, vibration and noise dampening at this point are generally most effective). Lighting should be checked frequently and maintained at levels sufficient to reduce vehicle-pedestrian accidents and ensure that product identification and other information can be easily read. Heat (or cold) stress prevention programmes should be implemented for workplaces in warm and humid climates and for selectors or fork-lift operators assigned to cold storage or freezer rooms, to ensure that workers receive adequate breaks, fluids, training and information and that other preventive measures are implemented. Finally, where diesel or petroleum-based fuels are used, exhaust systems should be periodically tested for emissions of carbon monoxide and nitrogen oxides to ensure that they are within safe levels. Proper maintenance of vehicles and restricting their use to adequately ventilated areas will also help reduce the risk of over-exposure to these emissions.

Safety hazards for fork-lift and vehicle operators

Vehicle-pedestrian accidents are a constant risk in any warehouse. Pedestrian lanes should be clearly marked and respected. All vehicle operators should receive training in the safe operation of the vehicle, including traffic rules and speed limits; refresher training should also be considered. Mirrors should be installed at busy intersections or at blind corners to enable vehicle operators to check for traffic or pedestrians before proceeding, and operators should sound their horn before proceeding; back-up beepers or signals may also be considered. Dockplates from loading and receiving docks to the truck, railroad car or barge need to be sufficient to support the load and adequately secured.

Table 2 gives a job safety analysis for fork-lift operators, with recommendations.

Table 2. Job safety analysis: Fork-lift operator.

Implementing ergonomic solutions will require closer coordination with fork-lift and vehicle manufacturers; relying solely upon operator training and traffic rules will not eliminate hazards by itself. In addition, safety and health regulatory agencies have prepared mandatory standards for the design and use of fork-lifts—for example, requiring overhead guards to offer protection against falling objects (see figure 3).

Figure 3. An overhead guard fitted to a fork-lift truck.

Safety hazards for order selectors

Table 3 is a job safety analysis listing most of the corrective actions necessary to reduce the safety and lifting hazards for order selectors. However, just as improved fork-lift design to reduce ergonomic risk factors requires closer coordination with vehicle manufacturers, reducing safety and lifting hazards for order selectors requires similar coordination with designers of racking systems, consultants who design and install warehouse control systems and engineered standards systems and the vendors who store their products in the warehouse. The latter can be enlisted to design products that are less bulky, weigh less and have better handles or grips. Rack manufacturers can be very helpful in designing and retrofitting rack systems which allow the selector to stand upright during selection.

Table 3. Job safety analysis: Order selector.

Consultants who design and install warehouse control systems and engineered standards need to be more aware of the health and safety risks concerning the effect of work intensification on manual material-handling injuries. NIOSH (1993a, 1995) has recommended that more objective forms of determining fatigue allowance, such as oxygen consumption or heart rate, be used. They have also recommended that the height of the pallet being constructed (the “cube”) be limited to no more than 150 cm, and that there be an “order break” after one pallet has been assembled by the order selector, thus increasing the frequency of recovery periods between orders. In addition to more frequent breaks, NIOSH has recommended restricting overtime for workers based on engineered standards, considering worker rotation and installing “light duty” programmes for order selectors who return from injury or leave.

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The transport sector encompasses industries that are involved in the transportation of goods and passengers throughout the world. This sector is structurally complex and vitally important to economies locally, nationally and globally.

Economic Importance

The transport sector is vitally important to the economic viability of nations. Transportation plays a key role in economically important factors such as employment, utilization of raw and manufactured goods, investment of private and public capital and generation of tax revenues.

In most industrialized countries, transport accounts for 2 to 12% of the paid employment (ILO 1992). In the United States alone, the Department of Transportation reported that in 1993, there were approximately 7.8 million employees in trucking-related firms (DOT 1995). The transport sector’s share in the gross domestic product (GDP) and total employment tends to decrease as the country’s income increases.

The transport sector is also a major consumer of raw materials and finished goods in most industrialized countries. For example, in the United States, the transport sector utilizes approximately 71% of all rubber produced, 66% of all petroleum refined, 24% of all zinc, 23% of all cement, 23% of all steel, 11% of all copper and 16% of all aluminium (Sampson, Farris and Shrock 1990).

Capital investment utilizing public and private funds to purchase trucks, ships, airplanes, terminals and other equipment and facilities easily exceeds hundreds of billions of dollars in industrialized countries.

The transport sector also plays a major role in generating revenues in the form of taxes. In industrialized countries, transport of passengers and freight is often heavily taxed (Sampson, Farris and Shrock 1990; Gentry, Semeijn and Vellenga 1995). Typically these taxes take the form of fuel taxes on gasoline and diesel fuels, and excise taxes on freight bills and passenger tickets, and easily exceed hundreds of billions of dollars annually.

Evolution of the Sector

In the early stages of the transport sector, geography greatly influenced what was the dominant mode of transportation. As advances were made in construction technology, it became possible to overcome many of the geographical barriers that limited the development of the transport sector. As a result, the modes of transport that have dominated the sector evolved in accordance with the technology available.

Initially, water travel over the oceans was the primary mode of transport of freight and passengers. As large rivers were navigated and canals were built, the volume of inland transport over the waterways increased significantly. In the late nineteenth century, transport over railways began to emerge as the dominant mode of transport. Rail transport, because of its ability to overcome natural barriers such as mountains and valleys through the use of tunnels and bridges, offered flexibility that waterways could not provide. Furthermore, unlike transport over waterways, transport over the rails was virtually unaffected by winter conditions.

Many national governments recognized the strategic and economic advantages of rail transport. Consequently, rail companies were awarded governmental financial assistance to facilitate the expansion of rail networks.

In the early twentieth century, the development of the combustion engine combined with the increased use of motor vehicles enabled road transport to become an increasingly popular mode of transport. As the highway and throughway systems were developed, road transport enabled door-to-door deliveries of goods. This flexibility far surpassed that of railways and waterways. Eventually, as advances were made in road construction and improvements were made to the internal combustion engine, in many parts of the world road transport became faster than rail transport. Consequently, road transport has become the most used mode of transport of goods and passengers.

The transport sector continued to evolve with the advent of airplanes. The use of airplanes as a means to transport freight and passengers began during the Second World War. Initially, airplanes were primarily used to transport mail and soldiers. However, as aircraft construction was perfected and an increasing number of persons learned to operate airplanes, air transport grew in popularity. Today, air transport is a very fast, reliable mode of transport. However, in terms of total tonnage, air transport handles only a very small percentage of freight.

Structure of the Sector

Information on the structure of rail systems in industrialized countries is generally reliable and comparable (ILO 1992). Similar information on road systems is somewhat less reliable. Information on the structure of waterways is reliable, having not changed substantially in the past few decades. However, similar information regarding developing countries is scarce and unreliable.

European countries developed economic and political blocs that have had a significant impact on the transport sector. In Europe, road transport dominates the movement of freight and passengers. Trucking, with a heavy emphasis on less-than-trailer-load freight, is conducted by small national and regional carriers. This industry is heavily regulated and highly fractured. Since the early 1970s, the total volume of freight transported by road has increased by 240%. Conversely, rail transport has declined by approximately 8% (Violland 1996). However, several European countries are working diligently to increase the efficiency of rail transport and are promoting intermodal transport.

In the United States, the primary mode of transport is over the roadways. The Department of Transportation, Office of Motor Carriers, reported in 1993 that there were over 335,000 firms operating medium and heavy trucks (DOT 1995). This included large companies that transport their own products, smaller private firms, and for-hire truckload and less-than-truckload common and contract carriers. The majority of these fleets (58%) operate six or fewer trucks. These companies operate a total of 1.7 million combination units, 4.4 million single-unit medium and heavy trucks and 3.8 million trailers. The road system in the United States increased by roughly 2% from 1980 to 1989 (ILO 1992).

The rail systems in the United States have declined, due primarily to the loss of Class 1 status of some rail lines, and due to the abandonment of less profitable lines. Canada has increased its rail system by some 40%, due mainly to a change in the classification system. The road system in Canada has decreased by 9% (ILO 1992).

In the industrialized nations of the Pacific Rim, there is great variability of the rail and road systems, due mainly to the different levels of industrialization of the respective countries. For example, rail and road networks in the Republic of Korea are similar to those in Europe, whereas in Malaysia, the rail and road networks are significantly smaller, but experiencing tremendous growth rates (over 53% for roads since 1980) (ILO 1992).

In Japan, the transport sector is heavily dominated by road transport, which accounts for 90.5% of the total Japanese freight transport tonnage. Approximately 8.2% of the tonnage is transported by water and 1.2% by rail (Magnier 1996).

Developing countries in Asia, Africa and Latin America typically suffer from inadequate transport systems. There is significant work underway to improve the systems, but a lack of hard currency, skilled workers and equipment inhibits the growth. Transport systems have grown significantly in Venezuela, Mexico and Brazil.

The Middle East in general has experienced growth in the transport sector, with countries such as Kuwait and Iran leading the way. It should be noted that due to the large size of the countries, sparse populations and arid climatic conditions, unique problems are encountered that limit the development of transport systems in this region.

An overview of railroad and road systems for selected countries and world regions is shown in figure 1 and figure 2.

Figure 1. World road network distribution 1988-89, kilometers.

Figure 2. World railroad network distribution, 1988-89, in kilometers.

Workforce Characteristics

The transportation sector contributes significantly to employment in most countries in both the private and public sectors. However, as per capita income increases, the impact of the sector on total employment decreases. The overall number of workers in the transport industries has declined steadily since the 1980s. This loss of workforce in the sector is due to several factors, especially technological advances that have automated many of the jobs related to the construction, maintenance and operation of transport systems. In addition, many countries have passed legislation which deregulated many transport-related industries; this has ultimately resulted in the loss of jobs.

Workers who are currently employed in transport-related industries must be highly skilled and competent. Due to the rapid advances in technology experienced in the transport sector, these workers and prospective workers must receive continual training and retraining.

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